Storage heating controls

[Sandtree]

Our storage heating currently has a single control thats marked min-max.

This links up to an outside temperature probe and then by reference to the manual it shows what percentage of power is put through the floor heating during the off peak power hours. Eg no matter the setting you get 100% of power if its below 3C, at 8C you'd get no heating at min, circa 50% at the mid point and 100% at max.

We now have a new controller thats waiting installation which not only has the min-max controller but has a number of hours (1-7). One obvious advantage would be to cap the power useage at below 3C as you'll still get 100% but could now limit it to a shorter time than the full 7 hours of off peak.

So we effectively currently have it at the mid point and 7 hours so at 8C would get half power for full time but we could once the controller is change alter that to full power for half time. In my uneducated mind this should cost the same but mean we get too little heat when its very cold and continue to get a bit of heat when its actually mild. Would there be any other advantage of full power/half time -v- half power/full time?

 

[JohnW2]

Our storage heating currently has a single control thats marked min-max. .... ... shows what percentage of power is put through the floor heating during the off peak power hours.

Are we talking about storage heating, floor heating or both?

Kind Regards, John

 

[Sandtree]

It has been descrived as having storage heating that is in the floor. It has a central control unit, outside temp sensor and a on/off switch in each room. It only operated on the off peak power with the standard idea of using the thermal mass of the concrete floor to heat up on the cheap overnight power and release it through the day in the rooms.

In the lounge/diner and bedrooms we also have in ceiling heating controlled by thermostates in each room that can operate 24/7. The two systems are independent other than for the fact the floor heats the air that thermostates for the ceilings obviously are measuring.

 

[JohnW2]

It has been descrived as having storage heating that is in the floor. It has a central control unit, outside temp sensor and a on/off switch in each room. It only operated on the off peak power with the standard idea of using the thermal mass of the concrete floor to heat up on the cheap overnight power and release it through the day in the rooms.

OK - so you have no 'storage heaters' as such (with their own internal 'bricks' for thermal storage), the only heating being that of the concrete floors?

So we effectively currently have it at the mid point and 7 hours so at 8C would get half power for full time but we could once the controller is change alter that to full power for half time. In my uneducated mind this should cost the same but mean we get too little heat when its very cold and continue to get a bit of heat when its actually mild. Would there be any other advantage of full power/half time -v- half power/full time?

I would think that it would be very difficult to predict the relative merits of those two options - either in terms of cost or (daytime) heating - so you will probably have to determine that 'by experiment'.

Half as long a period of heating at twice the power does not necessarily equate to 'the same', either in terms of electricity consumption or amount of heat stored (and released during the day), since there is presumably also thermostatic control based on the floor/heating element temperature.

If you tried the 'half time/full power' option, would you have control over when those 'half time' hours happened? If you did that, it would presumably be desirable for it to be the last 3.5 hours of the cheap-rate period, if you were to maximise heat availability during the daytime.

As I've said, I suspect that it will have to be 'suck it and see', but others may be able to advise you better on the basis of experience.

Is this (and the 'ceiling heating' you mentioned) your only (or main) form of space heating?

Kind Regards, John

 

[Sandtree]

OK - so you have no 'storage heaters' as such (with their own internal 'bricks' for thermal storage), the only heating being that of the concrete floors?

No storage heaters (as in the wall mounted units with bricks in them), just the floor heating that works in the same way as storage heating but uses the concrete slab rather than bricks.

Half as long a period of heating at twice the power does not necessarily equate to 'the same', either in terms of electricity consumption or amount of heat stored (and released during the day), since there is presumably also thermostatic control based on the floor/heating element temperature.

The internal thermostates don't control the floor heating, only the ceiling, and we've never had the ceiling heating on overnight - turn the thermostates down to "0" before bed. The external temp probe is the only temperature measure in connection with the floors and having had it replaced in December, its a very simple small circuit board in a plastic housing on the outside wall at around head height (relative to our floor).

I appreciate with the "bigger picture" that if we underheat the floor then we'll end up using the ceiling more and thus total power consumption may be the same/similar either way I was thinking more simplistic in terms of just the powering the floor over night.

If you tried the 'half time/full power' option, would you have control over when those 'half time' hours happened?

No, the new controller only as a dial with hours on it. The controller only receives power from the off peak too so has no 24/7 timer in it and therefore must be only the first X hours of it receiving power each night.

As I've said, I suspect that it will have to be 'suck it and see', but others may be able to advise you better on the basis of experience.

Is this (and the 'ceiling heating' you mentioned) your only (or main) form of space heating

We currently have the controlled but havent had it fitted yet - a series of arguments between the landlord, the supplier of the parts and the electrician over who's job it is and how it should work etc. I was trying to work out if we should be pushing its fitting or just throw it in the cupboard and stick with the old one.

The overnight floor and 24/7 ceiling is all the heating in the property. Despite large 80s double glazing windows with trickle vents open the property remains warm. Most the time the floor heating alone is enough and even when it was broken (outside sensor broke) we only really needed the ceiling heating in the evenings when it was cold outside... guess the ceiling/floor heating of the units above/below does a reasonable job of warming our place too.

 

[JohnW2]

The internal thermostates don't control the floor heating, only the ceiling, and we've never had the ceiling heating on overnight - turn the thermostates down to "0" before bed.

Although there are no user-adjustable internal thermostats, there will very probably be thermostats in the floor in order to prevent either floor or in-floor heating element rising to an unacceptable (perhaps dangerous) temperature. That's why I said that full-power/half-time might not be 'the same' as 'half-power/full-time', since in the former case, 'internal' thermostats might result in the element not be powered for all of that 'half time'' (e.g. in order to keep element temperature to a safe level)

No, the new controller only as a dial with hours on it. The controller only receives power from the off peak too so has no 24/7 timer in it and therefore must be only the first X hours of it receiving power each night.

As I implied, that suggests that the 'full-power/half-time' option may not be so clever, since the heating of the floor would stop a good few hours before you even woke up.

Kind Regards, John

 

[Sandtree]

Although there are no user-adjustable internal thermostats, there will very probably be thermostats in the floor in order to prevent either floor or in-floor heating element rising to an unacceptable (perhaps dangerous) temperature. That's why I said that full-power/half-time might not be 'the same' as 'half-power/full-time', since in the former case, 'internal' thermostats might result in the element not be powered for all of that 'half time'' (e.g. in order to keep element temperature to a safe level)

There could be but I don't believe there is - the system was installed when the development went up in the 80s so not sure if regs were more relaxed back then, certainly the electrician said our current consumer unit wouldnt pass regs.

The suppliers of the heating came out to see what the problem was when the heating wasn't working. They measured the resistance across the external probe and at the on/off switch in each room. For the former they looked up the current temp and a resistence chart and said it was clearly faulty. For the floors they said they were all fine other than the hallway which had "a broken element". They said they had a machine they could run over the floor to find where the break was but wanted some assurance the landlord would be wanting a fix before doing so (he said no).

There was no mention of anything other than the element breaking as the cause and unlike the probe, no charts to check if it was functional or not etc. Obviously not definitive proof that there isnt anything more complex set in the concrete but I'd hope that were there then there'd be come consideration of how to replace it whereas the heating element is set into the concrete floor itself